GIR 1 TERMS OF HEADING 8421 INCLUDES CENTRIFUGES; FILTERING OR PURIFYING MACHINERY AND APPARATUS, FOR LIQUIDS AND GASES. GIR 6 TERMS OF ONE DASH SUBHEADING- FILTERING OR PURIFYING MACHINERY AND APPARATUS FOR LIQUIDS. TERMS OF TWO DASH SUBHEADING 8421.21 FOR FILTERING OR PURIFYING WATER. CN CODE 842121.90 OTHER THAN FOR USE IN CIVIL AIRCRAFT.